Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, Problem at the Gas Pump!!Car wont start on first Crank in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; I have a 2003 CTS love it to death butt having a problem with it when I go to get ...

Problem at the Gas Pump!!Car wont start on first Crank

I have a 2003 CTS love it to death butt having a problem with it when I go to get Gas..

The thing runs like a top and starts like a champ..Only When I go fill up on Gas it dosen't want to start on the first turn of the key.. The second turn I have to mash the gas pedal all the way to the floor then it starts right up...After that I can turn it off and on with no problem. Even when I have my foot off the gas..Until next time I go get gas..Need Help Don't know whats going on with my car...

Re: Problem at the Gas Pump!!Car wont start on first Crank

It is usually on the right side of the engine towards the rear. (look under the beauty cover on the 3.6)
It is a large solenoid and you'll find two wires on one connector and a line coming in and going out that looks like a nylon fuel line.
The connections are easy to undo.

What happens is that during fueling the EVAP canister gets saturated.
If the purge solenoid sticks open those extra fumes will be drawn in and it will cause the mixture to be so rich it won't start.
The only way to get it going usually is "clear flood" mode which is basically holding the accelerator pedal down to the floor to get enough air in and cut back fuel delivery on start up.

There could be other issues but this is a classic symptom of the solenoid when it won't start or starts hard after a fill up.
I did one last week.

Re: Problem at the Gas Pump!!Car wont start on first Crank

GM loves "pulse width modulation".
It is a method of controlling things by varying the on/off time of an electrical circuit.

All the interior lamps that dim are controlled that way, in fact almost everything on the car that isn't analog is controlled by PWM.
The purge solenoid is constantly cycled once the conditions for activation are met.
It allows them to vary the purge rate without having to make a variable opening device.
They can just leave it on for longer periods of time to make it open more.
If you know it is there, and you hear it, it is hard to "un-hear" it.

Re: Problem at the Gas Pump!!Car wont start on first Crank

Originally Posted by ewill3rd

GM loves "pulse width modulation".
It is a method of controlling things by varying the on/off time of an electrical circuit.

All the interior lamps that dim are controlled that way, in fact almost everything on the car that isn't analog is controlled by PWM.
The purge solenoid is constantly cycled once the conditions for activation are met.
It allows them to vary the purge rate without having to make a variable opening device.
They can just leave it on for longer periods of time to make it open more.
If you know it is there, and you hear it, it is hard to "un-hear" it.

Is this what causes the ticking? Definitely beyond me as far as understanding the workings of PWM. I'd need a diagram haha.

Re: Problem at the Gas Pump!!Car wont start on first Crank

Yeah, just think of it as someone turning the lights on and off real fast to control how bright they are.
The longer they leave them on the brighter they are.
There is a plunger that moves and as it is cycled on and off, it clicks shut.

Re: Problem at the Gas Pump!!Car wont start on first Crank

hey i just went RockAuto.com and purchased one for around about $22 shipped. its from ACDELCO and i believe the part number is 2142230. if that doesnt work just type in CTS, Purge Solenoid and it should come up.

Re: Problem at the Gas Pump!!Car wont start on first Crank

Luke is the master of part numbers.

PM "Lindsay Cadillac Parts", post a request in the vendors area under Lindsay Cadillac or parouse for his phone number and bug him personally.
He gives discounts to forum members for a more than fair price.